This invention relates generally to drive systems, and more particularly, to a drive system with improved acoustic qualities. In one implementation a reduced-noise media drive system is provided for an office machine, such as a printer, copier, telecopier, scanner or the like. Other systems using a drive system also may benefit from the invention.
Conventionally, office machines which move a media sheet to receive print recording or scanning use gear train speed reductions for media advance. For every one rotation of a drive motor shaft there are x rotations of a media roller (where x typically is less than 1), as determined by the gear train reductions. For drive systems using open loop stepper motors, gear quality is important for accurate media advance. To further improve accuracy and precision, encoders may be used on the media roller's drive shaft. Another solution for improving accuracy and precision has been to use DC servo motors, instead of the open loop stepper motors.
For desktop products it is desirable that systems occupy little desk space and have minimal cost. Further, the media must advance fast enough to meet system throughput requirements. As a result, gear trains have been used which have high velocity and high tooth meshing frequencies. However, such approach to increasing speed is accompanied by an increase in noise. As system requirements continue to call for increasingly high speeds, the increasingly high tooth meshing frequencies result in systems exceeding desired acoustical limits. Accordingly, there is a need for a quieter drive system which can achieve desired media advance velocities without compromising advance accuracy or precision.